Touch panel

ABSTRACT

The disclosure provides a touch panel having a touch sensing region and a peripheral circuit region. The touch panel includes a transparent substrate, a touch sensing layer, a first fanout circuit, and a second fanout circuit. The touch sensing layer is located above the transparent substrate and is disposed in the touch sensing region, in which the touch sensing layer has plural sensing units. The first fanout circuit is disposed in the peripheral circuit region. The second fanout circuit is disposed in the peripheral circuit region and is located above the first fanout circuit. The first fanout circuit and the second fanout circuit are electrically connected to the sensing units respectively. A projection of the first fanout circuit on the transparent substrate and a projection of the second fanout circuit on the transparent substrate at least partially overlap each other.

RELATED APPLICATIONS

This application claims priority to China Application Serial Number201710784755.9, filed Sep. 1, 2017, which is herein incorporated byreference.

BACKGROUND Field of Invention

The present invention relates to a touch panel. More particularly, thepresent invention relates to a touch panel having a first fanout circuitoverlapping a second fanout circuit.

Description of Related Art

With the development of the touch sensing technology, the quality of thetouch device has been continuously improving. For a touch device, how toincrease the available screen area is always an important issue in theindustry. For example, smart phones with narrow border design havealready become mainstream in the current market.

However, border widths are determined by the manufacturing process ofconductive circuits, and the manufacturing process for the conductivecircuits such as printing, laser, photolithography, and other processeshave reached their limit on the line width of the conductive circuitry.So how to achieve an even more extremely narrow border under thelimitations of aforementioned existing processes is an imperativeproblem to be solved in the industry.

SUMMARY

The disclosure provides a touch panel having a touch sensing region anda peripheral circuit region. The touch panel includes a transparentsubstrate, a touch sensing layer, a first fanout circuit, and a secondfanout circuit. The touch sensing layer is located above the transparentsubstrate and is disposed in the touch sensing region, in which thetouch sensing layer has a plurality of sensing units. The first fanoutcircuit is disposed in the peripheral circuit region. The second fanoutcircuit is disposed in the peripheral circuit region and is locatedabove the first fanout circuit, in which the first fanout circuit andthe second fanout circuit are electrically connected to the sensingunits respectively, in which a projection of the first fanout circuit onthe transparent substrate and a projection of the second fanout circuiton the transparent substrate at least partially overlaps each other.

In some embodiments, the touch panel further includes a patternedinsulating layer. The patterned insulating layer is located between thefirst fanout circuit and the second fanout circuit, in which the firstfanout circuit and the second fanout circuit are electrically insulatedfrom each other by the patterned insulating layer.

In some embodiments, the patterned insulating layer includes pluralvias. The second fanout circuit is connected to the sensing unitsthrough a conductive material in some of the vias of the patternedinsulating layer respectively, in which the conductive material and thefirst fanout circuit are made of a substantially similar material.

In some embodiments, the touch panel further includes at least a bridgestructure. The bridge structure is connected between adjacent two of thesensing units, in which the at least one bridge structure includes aninsulating bump and a connecting line.

In some embodiments, the connecting line crosses over the insulatingbump and is electrically connected to the adjacent two of the sensingunits.

In some embodiments, the connecting line is electrically connected tothe adjacent two of the sensing units through at least an opening of theinsulating bump.

In some embodiments, the patterned insulating layer and the insulatingbump are made of a substantially similar material.

In some embodiments, the connecting line and the second fanout circuitare made of a substantially similar material.

In some embodiments, the first fanout circuit has a first widZith, thesecond fanout circuit has a second width, in which a projection of thefirst width of the first fanout circuit on the transparent substrateentirely overlaps a projection of the second width of the second fanoutcircuit on the transparent substrate.

In some embodiments, the first fanout circuit has a first width, thesecond fanout circuit has a second width, in which a projection of thefirst width of the first fanout circuit on the transparent substrate ispartially shifted from a projection of the second width of the secondfanout circuit on the transparent substrate.

It is to be understood that both the foregoing general description andthe following detailed description are by examples, and are intended toprovide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention can be more fully understood by reading the followingdetailed description of the embodiment, with reference made to theaccompanying drawings as follows:

FIG. 1A illustrates a schematic top view of a touch panel according toan embodiment of the present disclosure;

FIG. 1B illustrates a cross-sectional view of the touch panel along aline 1B-1B shown in FIG. 1A;

FIG. 1C illustrates a cross-sectional view of the touch panel along aline 1C-1C shown in FIG. 1A;

FIG. 1D illustrates a cross-sectional view of the touch panel along aline 1D-1D shown in FIG. 1A;

FIG. 2 illustrates a schematic cross-sectional view of a touch panelaccording to an embodiment of the present disclosure;

FIG. 3A illustrates a schematic diagram of sensing units of a touchpanel 300 according to another embodiment of the present disclosure;

FIG. 3B illustrates a cross-sectional view of a touch panel along a line3B-3B shown in FIG. 3A; and

FIG. 3C illustrates a cross-sectional view of a peripheral circuitregion of the touch panel.

DETAILED DESCRIPTION

Reference will now be made in detail to the present embodiments of theinvention, examples of which are illustrated in the accompanyingdrawings. Wherever possible, the same reference numbers are used in thedrawings and the description to refer to the same or like parts.

Please refer to FIG. 1A to FIG. 1D. FIG. 1A illustrates a schematic topview of a touch panel 100 according to an embodiment of the presentdisclosure. FIG. 1B illustrates a cross-sectional view of the touchpanel 100 along a line 1B-1B shown in FIG. 1A. FIG. 1C illustrates across-sectional view of the touch panel 100 along a line 1C-1C shown inFIG. 1A. FIG. 1D illustrates a cross-sectional view of the touch panel100 along a line 1D-1D shown in FIG. 1A. As shown in FIG. 1A, the touchpanel 100 of the present embodiment has a touch sensing region TA and aperipheral circuit region PA, and the touch panel 100 includes atransparent substrate 110, a touch sensing layer 120, a patternedinsulating layer 130, a first fanout circuit 140, and a second fanoutcircuit 150. For example, in the present embodiment, the transparentsubstrate 110 may be made of Polyethylene terephthalate (PET), cyclicolefin polymer (COP), polyimide (PI), polyethylene naphthalate (PEN),polycarbonate (PC), or any other flexible plastic materials.

In particular, as the present embodiment shown in FIG. 1A and FIG. 1B,the touch sensing layer 120 is located above the transparent substrate110, and the touch sensing layer 120 is disposed in the touch sensingregion TA, in which the touch sensing layer 120 has plural sensing units121. For example, in the present embodiment, the sensing units 121 aremade of transparent conductive materials such as Indium tin oxide,indium zinc oxide, aluminum tin oxide, aluminum zinc oxide, indiumgermanium zinc oxide, any appropriate oxide, or a stack of at least twolayers of the aforementioned materials. In some embodiments, the firstfanout circuit and the second fanout circuit are electrically connectedto a first group of the sensing units and a second group of the sensingunits respectively.

As the present embodiment shown in FIG. 1A and FIG. 1B, the touchsensing layer 120 also includes at least one bridge structure 123. Thebridge structure 123 is connected between two adjacent sensing units121, in which the at least one bridge structure 123 includes aninsulating bump 123 a and a connecting line 123 b. The connecting line123 b is used to connect the sensing units 121. The insulating bump 123a is disposed between the connecting line 123 b and the sensing units121.

On the other hand, as the embodiment shown in FIG. 1A and FIG. 1B, thefirst fanout circuit 140 is disposed in the peripheral circuit regionPA, and the second fanout circuit 150 is disposed in the peripheralcircuit region PA and is located above the first fanout circuit 140. Thefirst fanout circuit 140 and the second fanout circuit 150 iselectrically connected to the sensing units 121 respectively, in which aprojection of the first fanout circuit 140 on the transparent substrate110 at least partially overlaps a projection of the second fanoutcircuit 150 on the transparent substrate 110, and the first fanoutcircuit 140 and second fanout circuit 150 are insulated from each other.More particularly, as the present embodiment shown in FIG. 1B, thepatterned insulating layer 130 is located between the first fanoutcircuit 140 and the second fanout circuit 150, and in which the firstfanout circuit 140 and the second fanout circuit 150 are electricallyinsulated from each other by the patterned insulating layer 130.

For example, as the embodiment shown in FIG. 1A and FIG. 1B, the firstfanout circuit 140 has a first width D1, the second fanout circuit 150has a second width D2. The projection of the first width D1 of the firstfanout circuit 140 on the transparent substrate 110 entirely overlaps aprojection of the second width D2 of the second fanout circuit 150 onthe transparent substrate 110. In some embodiments, the first width D1is equal to the second width D2.

As such, by configuring the first fanout circuit 140 and the secondfanout circuit 150 on different levels, and making the projection of thefirst fanout circuit 140 and the projection of the second fanout circuit150 at least partially overlap with each other on the transparentsubstrate 110, a width of the peripheral circuit region PA of the touchpanel 100 may be reduced, and thus the pursuing for an extreme narrowborder is achieved.

On the other hand, as the embodiment shown in FIG. 1C and FIG. 1D, thepatterned insulating layer 130 includes plural vias 131. The secondfanout circuit 150 is connected to the sensing units 121 through aconductive material 140′ in some of the vias 131 of the patternedinsulating layer 130 respectively. And as the embodiment shown in FIG.1C, the patterned insulating layer 130 is located in the peripheralcircuit region PA and bridges the sensing units 121 by the conductivematerial 140′ in the vias 131. The patterned insulating layer 130 has athickness D, which is roughly less than 23 um.

On the other hand, as the present embodiment shown in FIG. 1A and FIG.1D, the touch panel 100 further includes an extending circuit area BA.The first fanout circuit 140 and the second fanout circuit 150 extend tothe extending circuit area BA respectively and are connected withperipheral circuit. As the embodiment shown in FIG. 1D, for example, thesecond fanout circuit 150 is located above the first fanout circuit 140.

For example, in the present embodiment, the first fanout circuit 140 andthe sensing units 121 may be formed by performing a lithography etchingprocess on a stack of conductive materials (which at least includes twolayers of conductive materials). In addition, as the embodiment shown inFIG. 1C, the conductive material 140′ connecting the second fanoutcircuit 150 and the sensing units 121 may also be formed by theaforementioned process, that is, patterning the stack of conductivematerials with at least two layers of conductive materials. In otherwords, in the present embodiment, the sensing units 121 in the touchsensing region TA, the first fanout circuit 140 in the peripheralcircuit region PA, and the conductive material 140′ are all belonged toa same stack of conductive materials. In the present embodiment, theconductive material 140′ and the first fanout circuit 140 are made of asubstantially similar material.

And in the present embodiment, the insulating bump 123 a of the touchsensing region TA and the patterned insulating layer 130 of theperipheral circuit region PA are also belong to a same insulating layer,and may be formed by performing a patterning process to a same material.In other words, in the present embodiment, the material of theinsulating bump 123 a and the material of the patterned insulating layer130 are substantially the same. In the present embodiment, theinsulating bump 123 a and the patterned insulating layer 130 may beformed by performing a patterning process on an insulating materiallayer.

In addition, in the present embodiment, the connecting line 123 b in thetouch sensing region TA and the second fanout circuit 150 in theperipheral circuit region PA are both belong to a same conductivematerial layer, and may be formed in a same process. In other words, thematerial of the connecting line 123 b and the material of the secondfanout circuit 150 are substantially the same. In the presentembodiment, the connecting line 123 b and the second fanout circuit 150may be formed by performing a lithography etching process or a gridprinting process on a conductive material layer.

As such, the touch panel 100 may be manufactured by existing processes,there is no need to add additional processes to form the configurationthat the first fanout circuit 140 and the second fanout circuit 150 arelocated on different levels. As such, the projection of the first fanoutcircuit 140 and the projection of the second fanout circuit 150partially overlap each other on the transparent substrate 110, so awidth of the peripheral circuit region PA may be reduced, and thus thepursuing of the narrow border is achieved.

FIG. 2 illustrates a schematic cross-sectional view of a touch panel 200according to an embodiment of the present disclosure. The touch panel200 of the present embodiment is similar to the aforementioned touchpanel 100 shown in FIG. 1B. The difference between the touch panel 200and the touch panel 100 is: the projection of the first width D1 of thefirst fanout circuit 140 of the touch panel 200 on the transparentsubstrate 110 is shifted from the projection of the second width D2 ofthe second fanout circuit 150 of the touch panel 200 on the transparentsubstrate 110, but the projection of the first fanout circuit 140 andthe projection of the second fanout circuit 150 at least partiallyoverlap each other on the transparent substrate 110.

As such, as aforementioned, by configuring the first fanout circuit 140and the second fanout circuit 150 on different levels, and making theprojection of the first fanout circuit 140 and the projection of thesecond fanout circuit 150 partially overlap each other on thetransparent substrate 110, the peripheral circuit region PA of the touchpanel 200 may be reduced, and thus the pursuing of an extreme narrowborder is achieved.

FIG. 3A illustrates a schematic diagram of sensing units 321 of a touchpanel 300 according to another embodiment of the present disclosure.FIG. 3B illustrates a cross-sectional view of a touch panel 300 along aline 3B-3B shown in FIG. 3A. FIG. 3C illustrates a cross-sectional viewof a peripheral circuit region PA of the touch panel 300. The touchpanel 300 is similar to the aforementioned touch panel 100 shown in FIG.1B. The difference between the touch panel 300 and the touch panel 100is: as shown in FIG. 3B, in the present embodiment, the connecting line323 b of the bridge structure 323 of the touch panel 300 cross over theinsulating bump 323 a and electrically connects the two adjacent sensingunits 321. However, as the embodiment shown in FIG. 3C, the projectionof the first fanout circuit 140 and the projection of the second fanoutcircuit 150 at least partially overlap each other on the transparentsubstrate 110.

As such, by configuring the first fanout circuit 140 and the secondfanout circuit 150 on different levels, and making the projection of thefirst fanout circuit 140 and the second fanout circuit 150 at leastpartially overlap with each other on the transparent substrate 110, awidth of the peripheral circuit region PA of the touch panel 300 may bereduced, and thus the pursuing for an extreme narrow border is achieved.

In summary, in the embodiment of the present disclosure, by configuringthe first fanout circuit and the second fanout circuit on differentlevels and making the projection of the first fanout circuit and theprojection of the second fanout circuit at least partially overlap eachother on the transparent substrate, the width of the peripheral circuitregion is reduced, and thus the pursuing of an extreme narrow border isachieved. And the configuration of the touch panel of the presentdisclosure may be formed by existing processes, such that the firstfanout circuit and the second fanout circuit are located on differentlevels, so there is no need to add additional processes. The quality ofthe product is improved without increasing manufacturing cost.

Although the present invention has been described in considerable detailwith reference to certain embodiments thereof, other embodiments arepossible. Therefore, the spirit and scope of the appended claims shouldnot be limited to the description of the embodiments contained herein.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the structure of the presentinvention without departing from the scope or spirit of the invention.In view of the foregoing, it is intended that the present inventioncover modifications and variations of this invention provided they fallwithin the scope of the following claims.

What is claimed is:
 1. A touch panel having a touch sensing region and aperipheral circuit region, the touch panel comprising: a transparentsubstrate; a touch sensing layer located above the transparent substrateand disposed in the touch sensing region, wherein the touch sensinglayer has a plurality of sensing units; a first fanout circuit disposedin the peripheral circuit region; and a second fanout circuit disposedin the peripheral circuit region and located above the first fanoutcircuit, wherein the first fanout circuit and the second fanout circuitare electrically connected to the sensing units respectively, wherein aprojection of the first fanout circuit on the transparent substrate anda projection of the second fanout circuit on the transparent substrateat least partially overlap each other.
 2. The touch panel of claim 1,further comprising: a patterned insulating layer located between thefirst fanout circuit and the second fanout circuit, wherein the firstfanout circuit and the second fanout circuit are electrically insulatedfrom each other by the patterned insulating layer.
 3. The touch panel ofclaim 2, wherein the patterned insulating layer comprises a plurality ofvias, the second fanout circuit is connected to the sensing unitsthrough a conductive material in some of the vias of the patternedinsulating layer respectively, wherein the conductive material and thefirst fanout circuit are made of a substantially similar material. 4.The touch panel of claim 3, further comprising: at least one bridgestructure connected between adjacent two of the sensing units, whereinthe at least one bridge structure comprises an insulating bump and aconnecting line.
 5. The touch panel of claim 4, wherein the connectingline crosses over the insulating bump and is electrically connected tothe adjacent two of the sensing units.
 6. The touch panel of claim 4,wherein the connecting line is electrically connected to the adjacenttwo of the sensing units through at least an opening of the insulatingbump.
 7. The touch panel of claim 4, wherein the patterned insulatinglayer and the insulating bump are made of a substantially similarmaterial.
 8. The touch panel of claim 4, wherein the connecting line andthe second fanout circuit are made of a substantially similar material.9. The touch panel of claim 1, wherein the first fanout circuit has afirst width, the second fanout circuit has a second width, wherein aprojection of the first width of the first fanout circuit on thetransparent substrate entirely overlaps a projection of the second widthof the second fanout circuit on the transparent substrate.
 10. The touchpanel of claim 1, wherein the first fanout circuit has a first width,the second fanout circuit has a second width, wherein a projection ofthe first width of the first fanout circuit on the transparent substrateis partially shifted from a projection of the second width of the secondfanout circuit on the transparent substrate.